Field of the Invention
The present invention relates to an image processing apparatus handling image data. The image processing apparatus can be used in an image forming apparatus, such as a copying machine, a printer, a facsimile (FAX), and a multifunction peripheral including a plurality of these functions.
Description of the Related Art
Conventionally, copying machines, multifunction peripherals, and printers are known as image forming apparatuses for forming images on sheets. Further, recent image forming apparatuses are connected to servers via networks, and users can instruct execution of printing by specifying print data stored in the servers (Japanese Patent No. 4033857). When execution of such a “pull print” function is instructed, the image forming apparatus downloads print data from the server and starts printing.
In such systems, it is desirable for a user to be able to easily identify print data stored in a server. In a related innovative device therefor, there is a method for displaying a preview (or a thumbnail) of several pages of the print data. However, the print data necessary for generating a preview image is stored in the server and not stored in an image forming apparatus which performs the preview display. Therefore, if the image forming apparatus generates the preview image, it is necessary for the image forming apparatus to first download the print data from the server, and thus a delay occurs before the preview image can be displayed. Therefore, in an image forming system using the “pull print” function, it is desirable that the server generates preview images for several pages of the print data to be used for providing an outline of the print data and transmits the preview images to the image forming apparatus. On the other hand, it is also desirable that the image forming apparatus generates preview images of other pages to reduce the load on the server.